When ferroelectric liquid crystals are in a surface stabilized state, smectic layers align perpendicular to transparent substrates arranged on the top and the bottom. In this situation, each smectic layer is stable in either one of states, i.e., the state in which spontaneous polarization Ps points upward and the molecular axis is tilted to the right or the state in which the spontaneous polarization Ps points downward and the molecular axis is tilted to the left, and the two stable states exist simultaneously. An alignment film is formed on each of the top and bottom transparent substrates and a treatment for a direction of alignment is made to control the orientation of the smectic layers, and a liquid crystal panel with the direction of alignment oriented in the direction of the smectic layers of the ferroelectric liquid crystal is thus constructed. When an upward-directed electric field is applied across the ferroelectric liquid crystal panel, the liquid crystal is set into a rightward-tilted ferroelectric state with the molecules as a whole tilted rightward by an angle .theta. relative to the direction of alignment, and the molecular axis is also tilted rightward by .theta.. When the applied electric field is reversed to point downward, the liquid crystal is then set into a leftward-tilted ferroelectric state with the molecules as a whole tilted leftward by .theta. relative to the direction of alignment, and the molecular axis is also tilted leftward by .theta..
Antiferroelectric liquid crystals also possess spontaneous polarization in a surface stabilized state, and the smectic layers are oriented perpendicular to the top and bottom transparent substrates. However, unlike ferroelectric liquid crystals, the direction of the spontaneous polarization is changed every one or every few layers, mutually canceling the spontaneous polarization and thus obtaining a stable antiferroelectric state. In the antiferroelectric state, when the state in which the direction of the spontaneous polarization is tilted rightward exists alternately with the state in which the direction of the spontaneous polarization is tilted leftward, for example, the molecular axis direction in the antiferroelectric state is represented by the molecular axis direction (hereinafter described as the "average molecular axis direction") obtained by averaging the rightward and leftward tilting molecular axis directions, and this average molecular axis direction substantially coincides with the direction of alignment. When an upward-directed electric field is applied across a liquid crystal in such an antiferroelectric state, the rightward-tilted ferroelectric state results with the molecules as a whole tilted rightward by .theta.. When the electric field is applied in the downward direction by reversing the polarity of the applied voltage, the result is the leftward-tilted ferroelectric state with the molecules as a whole tilted leftward by .theta.. The polarization axis of one of the polarizers is aligned to coincide with the average molecular axis direction in the antiferroelectric state, and the polarization axis of the other polarizer is oriented at right angles to the polarization axis of the first polarizer. In the antiferroelectric state, since the polarization axis direction coincides with the average molecular axis direction, light is not transmitted; this state is the dark state. On the other hand, in both the rightward-tilted and leftward-tilted ferroelectric states, light is transmitted because of a displacement between the polarization axis direction and the average molecular axis direction; this state is the bright state.